Provided by: libmail-box-perl_3.010-3_all 
NAME
Mail::Box - manage a mailbox, a folder with messages
INHERITANCE
Mail::Box
is a Mail::Reporter
Mail::Box is extended by
Mail::Box::Dir
Mail::Box::File
Mail::Box::Net
SYNOPSIS
use Mail::Box::Manager;
my $mgr = Mail::Box::Manager->new;
my $folder = $mgr->open(folder => $ENV{MAIL}, ...);
print $folder->name;
# Get the first message.
print $folder->message(0);
# Delete the third message
$folder->message(3)->delete;
# Get the number of messages in scalar context.
my $emails = $folder->messages;
# Iterate over the messages.
foreach ($folder->messages) {...} # all messages
foreach (@$folder) {...} # all messages
$folder->addMessage(Mail::Box::Message->new(...));
Tied-interface:
tie my(@inbox), 'Mail::Box::Tie::ARRAY', $inbox;
# Four times the same:
$inbox[3]->print; # tied
$folder->[3]->print; # overloaded folder
$folder->message(3)->print; # usual
print $folder->[3]; # overloaded message
tie my(%inbox), 'Mail::Box::Tie::HASH', $inbox;
# Twice times the same
$inbox{$msgid}->print; # tied
$folder->messageId($msgid)->print;# usual
DESCRIPTION
A Mail::Box::Manager creates "Mail::Box" objects. But you already knew, because you started with the
Mail::Box-Overview manual page. That page is obligatory reading, sorry!
"Mail::Box" is the base class for accessing various types of mailboxes (folders) in a uniform manner.
The various folder types vary on how they store their messages, but when some effort those differences
could be hidden behind a general API. For example, some folders store many messages in one single file,
where other store each message in a separate file within the same directory.
No object in your program will be of type "Mail::Box": it is only used as base class for the real folder
types. "Mail::Box" is extended by
Extends "DESCRIPTION" in Mail::Reporter.
OVERLOADED
overload: ""
(stringification) The folder objects stringify to their name. This simplifies especially print
statements and sorting a lot.
example: use overloaded folder as string
# Three lines with overloading: resp. cmp, @{}, and ""
foreach my $folder (sort @folders)
{ my $msgcount = @$folder;
print "$folder contains $msgcount messages\n";
}
overload: @{}
When the folder is used as if it is a reference to an array, it will show the messages, like
messages() and message() would do.
example: use overloaded folder as array
my $msg = $folder->[3];
my $msg = $folder->message(3); # same
foreach my $msg (@$folder) ...
foreach my $msg ($folder->messages) ... # same
overload: cmp
(string comparison) folders are compared based on their name. The sort rules are those of the build-
in "cmp".
METHODS
Extends "METHODS" in Mail::Reporter.
Constructors
Extends "Constructors" in Mail::Reporter.
Mail::Box->new(%options)
Open a new folder. A list of labeled %options for the mailbox can be supplied. Some options pertain
to Mail::Box, and others are added by sub-classes.
To control delay-loading of messages, as well the headers as the bodies, a set of *_type options are
available. "extract" determines whether we want delay-loading.
-Option --Defined in --Default
access 'r'
body_delayed_type Mail::Message::Body::Delayed
body_type <folder specific>
coerce_options []
create <false>
extract 10240
field_type undef
fix_headers <false>
folder $ENV{MAIL}
folderdir undef
head_delayed_type Mail::Message::Head::Delayed
head_type Mail::Message::Head::Complete
keep_dups <false>
lock_file undef
lock_timeout 1 hour
lock_type Mail::Box::Locker::DotLock
lock_wait 10 seconds
locker undef
log Mail::Reporter 'WARNINGS'
manager undef
message_type <folder-class>::Message
multipart_type Mail::Message::Body::Multipart
remove_when_empty <true>
save_on_exit <true>
trace Mail::Reporter 'WARNINGS'
trusted <depends on folder location>
access => MODE
Access-rights to the folder. Folders are opened for read-only (which means write-protected) by
default! MODE can be
'r': read-only (default)
'a': append
'rw': read-write
'd': delete
These MODE has no relation to the modes actually used to open the folder files within this module.
For instance, if you specify "rw", and open the folder, only read permission on the folder-file is
required.
Be warned: writing a MBOX folder may create a new file to replace the old folder. The permissions
and owner of the file may get changed by this.
body_delayed_type => CLASS
The bodies which are delayed: which will be read from file when it is needed, but not before.
body_type => CLASS|CODE
When messages are read from a folder-file, the headers will be stored in a "head_type" object. For
the body, however, there is a range of choices about type, which are all described in
Mail::Message::Body.
Specify a CODE-reference which produces the body-type to be created, or a CLASS of the body which
is used when the body is not a multipart or nested. In case of a code reference, the header
structure is passed as first argument to the routine.
Do not return a delayed body-type (like "::Delayed"), because that is determined by the "extract"
option while the folder is opened. Even delayed message will require some real body type when they
get parsed eventually. Multiparts and nested messages are also outside your control.
For instance:
$mgr->open('InBox', body_type => \&which_body);
sub which_body($) {
my $head = shift;
my $size = $head->guessBodySize || 0;
my $type = $size > 100000 ? 'File' : 'Lines';
"Mail::Message::Body::$type";
}
The default depends on the mail-folder type, although the general default is
Mail::Message::Body::Lines. Please check the applicable manual pages.
coerce_options => ARRAY
Keep configuration information for messages which are coerced into the specified folder type,
starting with a different folder type (or even no folder at all). Messages which are coerced are
always fully read, so this kind of information does not need to be kept here.
create => BOOLEAN
Automatically create the folder when it does not exist yet. This will only work when access is
granted for writing or appending to the folder.
Be careful: you may create a different folder type than you expect unless you explicitly specify
Mail::Box::Manager::open(type).
extract => INTEGER | CODE | METHOD | 'LAZY'|'ALWAYS'
Defines when to parse (process) the content of the message. When the header of a message is read,
you may want to postpone the reading of the body: header information is more often needed than the
body data, so why parse it always together? The cost of delaying is not too high, and with some
luck you may never need parsing the body.
If you supply an INTEGER to this option, bodies of those messages with a total size less than that
number will be extracted from the folder only when necessary. Messages where the size (in the
"Content-Length" field) is not included in the header, like often the case for multiparts and
nested messages, will not be extracted by default.
If you supply a CODE reference, that subroutine is called every time that the extraction mechanism
wants to determine whether to parse the body or not. The subroutine is called with the following
arguments:
CODE->(FOLDER, HEAD)
where FOLDER is a reference to the folder we are reading. HEAD refers to the
Mail::Message::Head::Complete head of the message at hand. The routine must return a "true" value
(extract now) or a "false" value (be lazy, do not parse yet). Think about using the
Mail::Message::Head::guessBodySize() and Mail::Message::guessTimestamp() on the header to determine
your choice.
The third possibility is to specify the NAME of a method. In that case, for each message is
called:
FOLDER->NAME(HEAD)
Where each component has the same meaning as described above.
The fourth way to use this option involves constants: with "LAZY" all messages will be delayed.
With "ALWAYS" you enforce unconditional parsing, no delaying will take place. The latter is usuful
when you are sure you always need all the messages in the folder.
$folder->new(extract => 'LAZY'); # Very lazy
$folder->new(extract => 10000); # Less than 10kB
# same, but implemented yourself
$folder->new(extract => &large);
sub large($) {
my ($f, $head) = @_;
my $size = $head->guessBodySize;
defined $size ? $size < 10000 : 1
};
# method call by name, useful for Mail::Box
# extensions. The example selects all messages
# sent by you to be loaded without delay.
# Other messages will be delayed.
$folder->new(extract => 'sent_by_me');
sub Mail::Box::send_by_me($) {
my ($self, $header) = @_;
$header->get('from') =~ m/\bmy\@example.com\b/i;
}
field_type => CLASS
The type of the fields to be used in a header. Must extend Mail::Message::Field.
fix_headers => BOOLEAN
Broken MIME headers usually stop the parser: all lines not parsed are added to the body of the
message. With this flag set, the erroneous line is added to the previous header field and parsing
is continued. See Mail::Box::Parser::Perl::new(fix_header_errors).
folder => FOLDERNAME
Which folder to open (for reading or writing). When used for reading (the "access" option set to
"r" or "a") the mailbox should already exist and must be readable. The file or directory of the
mailbox need not exist if it is opened for reading and writing ("rw"). Write-permission is checked
when opening an existing mailbox.
The folder name can be preceded by a "=", to indicate that it is named relative to the directory
specified in new(folderdir). Otherwise, it is taken as relative or absolute path.
folderdir => DIRECTORY
Where are folders to be found by default? A folder-name may be preceded by a equals-sign ("=", a
"mutt" convension) to explicitly state that the folder is located below the default directory. For
example: in case "folderdir => '/tmp'" and "folder => '=abc'", the name of the folder-file is
'/tmp/abc'. Each folder type has already some default set.
head_delayed_type => CLASS
The headers which are delayed: which will be read from file when it is needed, but not before.
head_type => CLASS
The type of header which contains all header information. Must extend
Mail::Message::Head::Complete.
keep_dups => BOOLEAN
Indicates whether or not duplicate messages within the folder should be retained. A message is
considered to be a duplicate if its message-id is the same as a previously parsed message within
the same folder. If this option is false (the default) such messages are automatically deleted,
because it is considered useless to store the same message twice.
lock_file => FILENAME
The name of the file which is used to lock. This must be specified when locking is to be used.
lock_timeout => SECONDS
When the lock file is older than the specified number of SECONDS, it is considered a mistake. The
original lock is released, and accepted for this folder.
lock_type => CLASS|STRING|ARRAY
The type of the locker object. This may be the full name of a CLASS which extends
Mail::Box::Locker, or one of the known locker types "DotLock", "Flock", "FcntlLock", "Mutt", "NFS",
"POSIX", or "NONE". If an ARRAY is specified, then a Multi locker is built which uses the
specified list.
lock_wait => SECONDS
SECONDS to wait before failing on opening this folder.
locker => OBJECT
An OBJECT which extends Mail::Box::Locker, and will handle folder locking replacing the default
lock behavior.
log => LEVEL
manager => MANAGER
A reference to the object which manages this folder -- typically an Mail::Box::Manager instance.
message_type => CLASS
What kind of message objects are stored in this type of folder. The default is constructed from
the folder class followed by "::Message". For instance, the message type for "Mail::Box::POP3" is
"Mail::Box::POP3::Message"
multipart_type => CLASS
The default type of objects which are to be created for multipart message bodies.
remove_when_empty => BOOLEAN
Determines whether to remove the folder file or directory automatically when the write would result
in a folder without messages nor sub-folders.
save_on_exit => BOOLEAN
Sets the policy for saving the folder when it is closed. A folder can be closed manually (see
close()) or in a number of implicit ways, including on the moment the program is terminated.
trace => LEVEL
trusted => BOOLEAN
Flags whether to trust the data in the folder or not. Folders which reside in your "folderdir"
will be trusted by default (even when the names if not specified staring with "="). Folders which
are outside the folderdir or read from STDIN (Mail::Message::Construct::read()) are not trused by
default, and require some extra checking.
If you do not check encodings of received messages, you may print binary data to the screen, which
is a security risk.
The folder
$obj->addMessage($message, %options)
Add a message to the folder. A message is usually a Mail::Box::Message object or a sub-class
thereof. The message shall not be in an other folder, when you use this method. In case it is, use
Mail::Box::Manager::moveMessage() or Mail::Box::Manager::copyMessage() via the manager.
Messages with id's which already exist in this folder are not added.
BE WARNED that message labels may get lost when a message is moved from one folder type to an other.
An attempt is made to translate labels, but there are many differences in interpretation by
applications.
-Option--Default
share <not used>
share => BOOLEAN
Try to share the physical resource of the current message with the indicated message. It is
sometimes possible to share messages between different folder types. When the sharing is not
possible, than this option is simply ignored.
Sharing the resource is quite dangerous, and only available for a limited number of folder types,
at the moment only some Mail::Box::Dir folders; these file-based messages can be hardlinked (on
platforms that support it). The link may get broken when one message is modified in one of the
folders.... but maybe not, depending on the folder types involved.
example:
$folder->addMessage($msg);
$folder->addMessages($msg1, $msg2, ...);
$obj->addMessages(@messages)
Adds a set of message objects to the open folder at once. For some folder types this may be faster
than adding them one at a time.
example:
$folder->addMessages($msg1, $msg2, ...);
Mail::Box->appendMessages(%options)
Append one or more messages to an unopened folder. Usually, this method is called by the
Mail::Box::Manager::appendMessage(), in which case the correctness of the folder type is checked.
For some folder types it is required to open the folder before it can be used for appending. This
can be fast, but this can also be very slow (depends on the implementation). All %options passed
will also be used to open the folder, if needed.
-Option --Default
folder <required>
message undef
messages undef
share <false>
folder => FOLDERNAME
The name of the folder to which the messages are to be appended. The folder implementation will
avoid opening the folder when possible, because this is resource consuming.
message => MESSAGE
messages => ARRAY-OF-MESSAGES
One reference to a MESSAGE or a reference to an ARRAY of MESSAGEs, which may be of any type. The
messages will be first coerced into the correct message type to fit in the folder, and then will be
added to it.
share => BOOLEAN
Try to share physical storage of the message. Only available for a limited number of folder types,
otherwise no-op.
example:
my $message = Mail::Message->new(...);
Mail::Box::Mbox->appendMessages
( folder => '=xyz'
, message => $message
, folderdir => $ENV{FOLDERS}
);
better:
my Mail::Box::Manager $mgr;
$mgr->appendMessages($message, folder => '=xyz');
$obj->close(%options)
Close the folder, which usually implies writing the changes. This will return "false" when writing
is required but fails. Please do check this result.
WARNING: When moving messages from one folder to another, be sure to write the destination folder
before writing and closing the source folder. Otherwise you may lose data if the system crashes or
if there are software problems.
-Option --Default
force <false>
save_deleted false
write MODIFIED
force => BOOLEAN
Override the new(access) setting which was specified when the folder was opened. This option only
has an effect if its value is TRUE. NOTE: Writing to the folder may not be permitted by the
operating system, in which case even "force" will not help.
save_deleted => BOOLEAN
Do also write messages which where flagged to be deleted to their folder. The flag for deletion is
conserved (when possible), which means that a re-open of the folder may remove the messages for
real. See write(save_deleted).
write => 'ALWAYS'|'NEVER'|'MODIFIED'
Specifies whether the folder should be written. As could be expected, "ALWAYS" means always (even
if there are no changes), "NEVER" means that changes to the folder will be lost, and "MODIFIED"
only saves the folder if there are any changes.
example:
my $f = $mgr->open('spam', access => 'rw')
or die "Cannot open spam: $!\n";
$f->message(0)->delete
if $f->messages;
$f->close
or die "Couldn't write $f: $!\n";
$obj->copyTo($folder, %options)
Copy the folder's messages to a new folder. The new folder may be of a different type.
-Option --Default
delete_copied <false>
select 'ACTIVE'
share <not used>
subfolders <folder type dependent>
delete_copied => BOOLEAN
Flag the messages from the source folder to be deleted, just after it was copied. The deletion
will only take effect when the originating folder is closed.
select => 'ACTIVE'|'DELETED'|'ALL'|LABEL|!LABEL|FILTER
Which messages are to be copied. See the description of messages() about how this works.
share => BOOLEAN
Try to share the message between the folders. Some Mail::Box::Dir folder types do support it by
creating a hardlink (on UNIX/Linux).
subfolders => BOOLEAN|'FLATTEN'|'RECURSE'
How to handle sub-folders. When false (0 or "undef"), sub-folders are simply ignored. With
"FLATTEN", messages from sub-folders are included in the main copy. "RECURSE" recursively copies
the sub-folders as well. By default, when the destination folder supports sub-folders "RECURSE" is
used, otherwise "FLATTEN". A value of true will select the default.
example:
my $mgr = Mail::Box::Manager->new;
my $imap = $mgr->open(type => 'imap', host => ...);
my $mh = $mgr->open(type => 'mh', folder => '/tmp/mh',
create => 1, access => 'w');
$imap->copyTo($mh, delete_copied => 1);
$mh->close; $imap->close;
$obj->delete(%options)
Remove the specified folder file or folder directory (depending on the type of folder) from disk. Of
course, THIS IS DANGEROUS: you "may" lose data. Returns a "true" value on success.
WARNING: When moving messages from one folder to another, be sure to write the destination folder
before deleting the source folder. Otherwise you may lose data if the system crashes or if there are
software problems.
-Option --Default
recursive 1
recursive => BOOLEAN
example: removing an open folder
my $folder = Mail::Box::Mbox->new(folder => 'InBox', access => 'rw');
... some other code ...
$folder->delete;
example: removing an closed folder
my $folder = Mail::Box::Mbox->new(folder => 'INBOX', access => 'd');
$folder->delete;
$obj->folderdir( [$directory] )
Get or set the $directory which is used to store mail-folders by default.
example:
print $folder->folderdir;
$folder->folderdir("$ENV{HOME}/nsmail");
$obj->name()
Returns the name of the folder. What the name represents depends on the actual type of mailbox used.
example:
print $folder->name;
print "$folder"; # overloaded stringification
$obj->organization()
Returns how the folder is organized: as one "FILE" with many messages, a "DIRECTORY" with one message
per file, or by a "REMOTE" server.
$obj->size()
Returns the size of the folder in bytes, not counting in the deleted messages. The error in the
presented result may be as large as 10%, because the in-memory representation of messages is not
always the same as the size when they are written.
$obj->type()
Returns a name for the type of mail box. This can be "mbox", "mh", "maildir", or "pop3".
$obj->update(%options)
Read new messages from the folder, which where received after opening it. This is quite dangerous and
shouldn't be possible: folders which are open are locked. However, some applications do not use locks
or the wrong kind of locks. This method reads the changes (not always failsafe) and incorporates them
in the open folder administration.
The %options are extra values which are passed to the updateMessages() method which is doing the
actual work here.
$obj->url()
Represent the folder as a URL (Universal Resource Locator) string. You may pass such a URL as folder
name to Mail::Box::Manager::open().
example:
print $folder->url;
# may result in
# mbox:/var/mail/markov or
# pop3://user:password@pop.aol.com:101
Folder flags
$obj->access()
Returns the access mode of the folder, as set by new(access)
$obj->isModified()
Checks if the folder, as stored in memory, is modified. A true value is returned when any of the
messages is to be deleted, has changed, or messages were added after the folder was read from file.
WARNING: this flag is not related to an external change to the folder structure on disk. Have a look
at update() for that.
$obj->modified( [BOOLEAN] )
Sets whether the folder is modified or not.
$obj->writable()
Checks whether the current folder is writable.
example:
$folder->addMessage($msg) if $folder->writable;
The messages
$obj->current( [$number|$message|$message_id] )
Some mail-readers keep the current message, which represents the last used message. This method
returns [after setting] the current message. You may specify a $number, to specify that that message
number is to be selected as current, or a $message/$message_id (as long as you are sure that the
header is already loaded, otherwise they are not recognized).
example:
$folder->current(0);
$folder->current($message);
$obj->find($message_id)
Like messageId(), this method searches for a message with the $message_id, returning the
corresponding message object. However, "find" will cause unparsed message in the folder to be parsed
until the message-id is found. The folder will be scanned back to front.
$obj->findFirstLabeled( $label, [BOOLEAN, [$msgs]] )
Find the first message which has this $label with the correct setting. The BOOLEAN indicates whether
any true value or any false value is to be found in the ARRAY of $msgs. By default, a true value is
searched for. When a message does not have the requested label, it is taken as false.
example: looking for a labeled message
my $current = $folder->findFirstLabeled('current');
my $first = $folder->findFirstLabeled(seen => 0);
my $last = $folder->findFirstLabeled(seen => 0,
[ reverse $self->messages('ACTIVE') ] )
$obj->message( $index, [$message] )
Get or set a message with on a certain index. Messages which are flagged for deletion are counted.
Negative indexes start at the end of the folder.
example:
my $msg = $folder->message(3);
$folder->message(3)->delete; # status changes to `deleted'
$folder->message(3, $msg);
print $folder->message(-1); # last message.
$obj->messageId( $message_id, [$message] )
With one argument, returns the message in the folder with the specified $message_id. If a reference
to a message object is passed as the optional second argument, the message is first stored in the
folder, replacing any existing message whose message ID is $message_id. (The message ID of $message
need not match $message_id.)
!!WARNING!!: when the message headers are delay-parsed, the message might be in the folder but not
yet parsed into memory. In this case, use find() instead of messageId() if you really need a thorough
search. This is especially the case for directory organized folders without special indexi, like
Mail::Box::MH.
The $message_id may still be in angles, which will be stripped. In that case blanks (which origin
from header line folding) are removed too. Other info around the angles will be removed too.
example:
my $msg = $folder->messageId('<complex-message.id>');
$folder->messageId("<complex-message\n.id>", $msg);
my $msg = $folder->messageId('complex-message.id');
my $msg = $folder->messageId('garbage <complex-message.id> trash');
$obj->messageIds()
Returns a list of all message-ids in the folder, including those of messages which are to be deleted.
For some folder-types (like MH), this method may cause all message-files to be read. See their
respective manual pages.
example:
foreach my $id ($folder->messageIds) {
$folder->messageId($id)->print;
}
$obj->messages( <'ALL'|$range|'ACTIVE'|'DELETED'|$label| !$label|$filter> )
Returns multiple messages from the folder. The default is "ALL" which will return (as expected
maybe) all the messages in the folder. The "ACTIVE" flag will return the messages not flagged for
deletion. This is the opposite of "DELETED", which returns all messages from the folder which will
be deleted when the folder is closed.
You may also specify a $range: two numbers specifying begin and end index in the array of messages.
Negative indexes count from the end of the folder. When an index is out-of-range, the returned list
will be shorter without complaints.
Everything else than the predefined names is seen as labels. The messages which have that label set
will be returned. When the sequence starts with an exclamation mark (!), the search result is
reversed.
For more complex searches, you can specify a $filter, which is simply a code reference. The message
is passed as only argument.
example:
foreach my $message ($folder->messages) {...}
foreach my $message (@$folder) {...}
# twice the same
my @messages = $folder->messages;
my @messages = $folder->messages('ALL');
# Selection based on a range (begin, end)
my $subset = $folder->messages(10,-8);
# twice the same:
my @not_deleted= grep {not $_->isDeleted}
$folder->messages;
my @not_deleted= $folder->messages('ACTIVE');
# scalar context the number of messages
my $nr_of_msgs = $folder->messages;
# third message, via overloading
$folder->[2];
# Selection based on labels
$mgr->moveMessages($spam, $inbox->message('spam'));
$mgr->moveMessages($archive, $inbox->message('seen'));
$obj->nrMessages(%options)
Simply calls messages() in scalar context to return a count instead of the messages itself. Some
people seem to understand this better. Note that nrMessages() will default to returning a count of
"ALL" messages in the folder, including both "ACTIVE" and "DELETED".
The %options are passed to (and explained in) messages().
$obj->scanForMessages($message, $message_ids, $timespan, $window)
You start with a $message, and are looking for a set of messages which are related to it. For
instance, messages which appear in the 'In-Reply-To' and 'Reference' header fields of that message.
These messages are known by their $message_ids and you want to find them in the folder.
When all message-ids are known, then looking-up messages is simple: they are found in a plain hash
using messageId(). But Mail::Box is lazy where it can, so many messages may not have been read from
file yet, and that's the preferred situation, because that saves time and memory.
It is not smart to search for the messages from front to back in the folder: the chances are much
higher that related message reside closely to each other. Therefore, this method starts scanning the
folder from the specified $message, back to the front of the folder.
The $timespan can be used to terminate the search based on the time enclosed in the message. When
the constant string "EVER" is used as $timespan, then the search is not limited by that. When an
integer is specified, it will be used as absolute time in time-ticks as provided by your platform
dependent "time" function. In other cases, it is passed to timespan2seconds() to determine the
threshold as time relative to the message's time.
The $window is used to limit the search in number of messages to be scanned as integer or constant
string "ALL".
Returned are the message-ids which were not found during the scan. Be warned that a message-id could
already be known and therefore not found: check that first.
example: scanning through a folder for a message
my $refs = $msg->get('References') or return;
my @msgids = $ref =~ m/\<([^>]+\>/g;
my @failed = $folder->scanForMessages($msg, \@msgids, '3 days', 50);
Sub-folders
$obj->listSubFolders(%options)
Mail::Box->listSubFolders(%options)
List the names of all sub-folders to this folder, not recursively decending. Use these names as
argument to openSubFolder(), to get access to that folder.
For MBOX folders, sub-folders are simulated.
-Option --Default
check <false>
folder <from calling object>
folderdir <from folder>
skip_empty <false>
check => BOOLEAN
Should all returned foldernames be checked to be sure that they are of the right type? Each sub-
folder may need to be opened to check this, with a folder type dependent penalty (in some cases
very expensive).
folder => FOLDERNAME
The folder whose sub-folders should be listed.
folderdir => DIRECTORY
skip_empty => BOOL
Shall empty folders (folders which currently do not contain any messages) be included? Empty
folders are not useful to open, but may be useful to save to.
example:
my $folder = $mgr->open('=in/new');
my @subs = $folder->listSubFolders;
my @subs = Mail::Box::Mbox->listSubFolders(folder => '=in/new');
my @subs = Mail::Box::Mbox->listSubFolders; # toplevel folders.
$obj->nameOfSubFolder( $subname, [$parentname] )
Mail::Box->nameOfSubFolder( $subname, [$parentname] )
Returns the constructed name of the folder with NAME, which is a sub-folder of this current one. You
have either to call this method as instance method, or specify a $parentname.
example: how to get the name of a subfolder
my $sub = Mail::Box::Mbox->nameOfSubfolder('xyz', 'abc');
print $sub; # abc/xyz
my $f = Mail::Box::Mbox->new(folder => 'abc');
print $f->nameOfSubfolder('xyz'); # abc/xyz
my $sub = Mail::Box::Mbox->nameOfSubfolder('xyz', undef);
print $sub; # xyz
$obj->openRelatedFolder(%options)
Open a folder (usually a sub-folder) with the same options as this one. If there is a folder manager
in use, it will be informed about this new folder. %options overrule the options which where used
for the folder this method is called upon.
$obj->openSubFolder($subname, %options)
Open (or create, if it does not exist yet) a new subfolder in an existing folder.
example:
my $folder = Mail::Box::Mbox->new(folder => '=Inbox');
my $sub = $folder->openSubFolder('read');
$obj->topFolderWithMessages()
Mail::Box->topFolderWithMessages()
Some folder types can have messages in the top-level folder, some other can't.
Internals
$obj->coerce($message, %options)
Coerce the $message to be of the correct type to be placed in the folder. You can specify
Mail::Internet and MIME::Entity objects here: they will be translated into Mail::Message messages
first.
$obj->create($foldername, %options)
Mail::Box->create($foldername, %options)
Create a folder. If the folder already exists, it will be left unchanged. The folder is created,
but not opened! If you want to open a file which may need to be created, then use
Mail::Box::Manager::open() with the create flag, or Mail::Box::new(create).
-Option --Default
folderdir undef
folderdir => DIRECTORY
When the foldername is preceded by a "=", the "folderdir" directory will be searched for the named
folder.
$obj->determineBodyType($message, $head)
Determine which kind of body will be created for this message when reading the folder initially.
Mail::Box->foundIn( [$foldername], %options )
Determine if the specified folder is of the type handled by the folder class. This method is extended
by each folder sub-type.
The $foldername specifies the name of the folder, as is specified by the application. You need to
specified the "folder" option when you skip this first argument.
%options is a list of extra information for the request. Read the documentation for each type of
folder for type specific options, but each folder class will at least support the "folderdir" option:
-Option --Default
folderdir undef
folderdir => DIRECTORY
The location where the folders of this class are stored by default. If the user specifies a name
starting with a "=", that indicates that the folder is to be found in this default DIRECTORY.
example:
Mail::Box::Mbox->foundIn('=markov',
folderdir => "$ENV{HOME}/Mail");
Mail::Box::MH->foundIn(folder => '=markov');
$obj->lineSeparator( [<STRING|'CR'|'LF'|'CRLF'>] )
Returns the character or characters used to separate lines in the folder file, optionally after
setting it to STRING, or one of the constants. The first line of the folder sets the default.
UNIX uses a LF character, Mac a CR, and Windows both a CR and a LF. Each separator will be
represented by a "\n" within your program. However, when processing platform foreign folders,
complications appear. Think about the "Size" field in the header.
When the separator is changed, the whole folder me be rewritten. Although, that may not be required.
$obj->locker()
Returns the locking object.
$obj->read(%options)
Read messages from the folder into memory. The %options are folder specific. Do not call read()
yourself: it will be called for you when you open the folder via the manager or instantiate a folder
object directly.
NOTE: if you are copying messages from one folder to another, use addMessages() instead of read().
example:
my $mgr = Mail::Box::Manager->new;
my $folder = $mgr->open('InBox'); # implies read
my $folder = Mail::Box::Mbox->new(folder => 'Inbox'); # same
$obj->readMessages(%options)
Called by read() to actually read the messages from one specific folder type. The read() organizes
the general activities.
The %options are "trusted", "head_type", "field_type", "message_type", "body_delayed_type", and
"head_delayed_type" as defined by the folder at hand. The defaults are the constructor defaults (see
new()).
$obj->storeMessage($message)
Store the message in the folder without the checks as performed by addMessage().
$obj->toBeThreaded($messages)
The specified message is ready to be removed from a thread. This will be passed on to the mail-
manager, which keeps an overview on which thread-detection objects are floating around.
$obj->toBeUnthreaded($messages)
The specified message is ready to be included in a thread. This will be passed on to the mail-
manager, which keeps an overview on which thread-detection objects are floating around.
$obj->updateMessages(%options)
Called by update() to read messages which arrived in the folder after it was opened. Sometimes,
external applications dump messages in a folder without locking (or using a different lock than your
application does).
Although this is quite a dangerous, it only fails when a folder is updated (reordered or message
removed) at exactly the same time as new messages arrive. These collisions are sparse.
The options are the same as for readMessages().
$obj->write(%options)
Write the data to disk. The folder (a "true" value) is returned if successful. Deleted messages are
transformed into destroyed messages: their memory is freed.
WARNING: When moving messages from one folder to another, be sure to write (or close()) the
destination folder before writing (or closing) the source folder: otherwise you may lose data if the
system crashes or if there are software problems.
To write a folder to a different file, you must first create a new folder, then move all the
messages, and then write or close() that new folder.
-Option --Default
force <false>
save_deleted <false>
force => BOOLEAN
Override write-protection with new(access) while opening the folder (whenever possible, it may
still be blocked by the operating system).
save_deleted => BOOLEAN
Do also write messages which where flagged to be deleted to their folder. The flag for deletion is
conserved (when possible), which means that a re-open of the folder may remove the messages for
real. See close(save_deleted).
$obj->writeMessages(%options)
Called by write() to actually write the messages from one specific folder type. The "write"
organizes the general activities. All options to write() are passed to "writeMessages" as well.
Besides, a few extra are added by "write" itself.
-Option --Default
messages <required>
messages => ARRAY
The messages to be written, which is a sub-set of all messages in the current folder.
Other methods
$obj->timespan2seconds($time)
Mail::Box->timespan2seconds($time)
$time is a string, which starts with a float, and then one of the words 'hour', 'hours', 'day',
'days', 'week', or 'weeks'. For instance: '1 hour' or '4 weeks'.
Error handling
Extends "Error handling" in Mail::Reporter.
$obj->AUTOLOAD()
Inherited, see "Error handling" in Mail::Reporter
$obj->addReport($object)
Inherited, see "Error handling" in Mail::Reporter
$obj->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
Mail::Box->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
Inherited, see "Error handling" in Mail::Reporter
$obj->errors()
Inherited, see "Error handling" in Mail::Reporter
$obj->log( [$level, [$strings]] )
Mail::Box->log( [$level, [$strings]] )
Inherited, see "Error handling" in Mail::Reporter
$obj->logPriority($level)
Mail::Box->logPriority($level)
Inherited, see "Error handling" in Mail::Reporter
$obj->logSettings()
Inherited, see "Error handling" in Mail::Reporter
$obj->notImplemented()
Inherited, see "Error handling" in Mail::Reporter
$obj->report( [$level] )
Inherited, see "Error handling" in Mail::Reporter
$obj->reportAll( [$level] )
Inherited, see "Error handling" in Mail::Reporter
$obj->trace( [$level] )
Inherited, see "Error handling" in Mail::Reporter
$obj->warnings()
Inherited, see "Error handling" in Mail::Reporter
Cleanup
Extends "Cleanup" in Mail::Reporter.
$obj->DESTROY()
This method is called by Perl when an folder-object is no longer accessible by the rest of the
program.
DETAILS
Different kinds of folders
In general, there are three classes of folders: those who group messages per file, those who group
messages in a directory, and those do not provide direct access to the message data. These folder types
are each based on a different base class.
• File based folders Mail::Box::File
File based folders maintain a folder (a set of messages) in one single file. The advantage is that
your folder has only one single file to access, which speeds-up things when all messages must be
accessed at once.
One of the main disadvantages over directory based folders is that you have to construct some means
to keep all message apart. For instance MBOX adds a message separator line between the messages in
the file, and this line can cause confusion with the message's contents.
Where access to all messages at once is faster in file based folders, access to a single message is
(much) slower, because the whole folder must be read. However, in directory based folders you have
to figure-out which message you need, which may be a hassle as well.
Examples of file based folders are MBOX, DBX, and NetScape.
• Directory based folders Mail::Box::Dir
In stead of collecting multiple messages in one file, you can also put each message in a separate
file and collect those files in a directory to represent a folder.
The main disadvantages of these folders are the enormous amount of tiny files you usually get in your
file-system. It is extremely slow to search through your whole folder, because many files have to be
opened to do so.
The best feature of this organization is that each message is kept exactly as it was received, and
can be processed with external scripts as well: you do not need any mail user agent (MUA).
Examples of directory organized folders are MH, Maildir, EMH and XMH.
• Network (external) folders Mail::Box::Net
Where both types described before provide direct access to the message data, maintain these folder
types the message data for you: you have to request for messages or parts of them. These folders do
not have a filename, file-system privileges and system locking to worry about, but typically require
a hostname, folder and message IDs, and authorization.
Examples of these folder types are the popular POP and IMAP, and database oriented message storage.
Available folder types
• Mail::Box::Dbx (read only)
Dbx files are created by Outlook Express. Using the external (optional) Mail::Transport::Dbx module,
you can read these folders, even when you are running MailBox on a UNIX/Linux platform.
Writing and deleting messages is not supported by the library, and therefore not by MailBox. Read
access is enough to do folder conversions, for instance.
• Mail::Box::IMAP4 (partially)
The IMAP protocol is very complex. Some parts are implemented to create (sub-optimal but usable)
IMAP clients. Besides, there are also some parts for IMAP servers present. The most important
lacking feature is support for encrypted connections.
• Mail::Box::Maildir
Maildir folders have a directory for each folder. A folder directory contains "tmp", "new", and
"cur" sub-directories, each containing messages with a different purpose. Files with new messages
are created in "tmp", then moved to "new" (ready to be accepted). Later, they are moved to the "cur"
directory (accepted). Each message is one file with a name starting with timestamp. The name also
contains flags about the status of the message.
Maildir folders can not be used on Windows by reason of file-name limitations on that platform.
• Mail::Box::Mbox
A folder type in which all related messages are stored in one file. This is a very common folder
type for UNIX.
• Mail::Box::MH
This folder creates a directory for each folder, and a message is one file inside that directory.
The message files are numbered sequentially on order of arrival. A special ".mh_sequences" file
maintains flags about the messages.
• Mail::Box::POP3 (read/delete only)
POP3 is a protocol which can be used to retrieve messages from a remote system. After the connection
to a POP server is made, the messages can be looked at and removed as if they are on the local
system.
• Mail::Box::Netzwert
The Netzwert folder type is optimized for mailbox handling on a cluster of systems with a shared NFS
storage. The code is not released under GPL (yet)
Other folder types are on the (long) wishlist to get implemented. Please, help implementing more of
them.
Folder class implementation
The class structure of folders is very close to that of messages. For instance, a
Mail::Box::File::Message relates to a Mail::Box::File folder. The folder types are:
Mail::Box::Netzwert
Mail::Box::Mbox | Mail::Box::Maildir Mail::Box::POP3
| Mail::Box::Dbx | | Mail::Box::MH | Mail::Box::IMAP4
| | | | | | |
| | | | | | |
Mail::Box::File Mail::Box::Dir Mail::Box::Net
| | |
`--------------. | .---------------'
| | |
Mail::Box
|
|
Mail::Reporter (general base class)
By far most folder features are implemented in Mail::Box, so available to all folder types. Sometimes,
features which appear in only some of the folder types are simulated for folders that miss them, like
sub-folder support for MBOX.
DIAGNOSTICS
Warning: Changes not written to read-only folder $self.
You have opened the folder read-only --which is the default set by new(access)--, made modifications,
and now want to close it. Set close(force) if you want to overrule the access mode, or close the
folder with close(write) set to "NEVER".
Error: Copying failed for one message.
For some reason, for instance disc full, removed by external process, or read-protection, it is
impossible to copy one of the messages. Copying will proceed for the other messages.
Error: Destination folder $name is not writable.
The folder where the messages are copied to is not opened with write access (see new(access)). This
has no relation with write permission to the folder which is controlled by your operating system.
Warning: Different messages with id $msgid
The message id is discovered more than once within the same folder, but the content of the message
seems to be different. This should not be possible: each message must be unique.
Error: Folder $name is opened read-only
You can not write to this folder unless you have opened the folder to write or append with
new(access), or the "force" option is set true.
Error: Folder $name not deleted: not writable.
The folder must be opened with write access via new(access), otherwise removing it will be refused.
So, you may have write-access according to the operating system, but that will not automatically mean
that this "delete" method permits you to. The reverse remark is valid as well.
Error: Invalid timespan '$timespan' specified.
The string does not follow the strict rules of the time span syntax which is permitted as parameter.
Warning: Message-id '$msgid' does not contain a domain.
According to the RFCs, message-ids need to contain a unique random part, then an "@", and then a
domain name. This is made to avoid the creation of two messages with the same id. The warning
emerges when the "@" is missing from the string.
Error: No folder name specified.
You did not specify the name of a folder to be opened. Use the new(folder) option or set the "MAIL"
environment variable.
Error: Package $package does not implement $method.
Fatal error: the specific package (or one of its superclasses) does not implement this method where
it should. This message means that some other related classes do implement this method however the
class at hand does not. Probably you should investigate this and probably inform the author of the
package.
Error: Unable to create subfolder $name of $folder.
The copy includes the subfolders, but for some reason it was not possible to copy one of these.
Copying will proceed for all other sub-folders.
Error: Writing folder $name failed
For some reason (you probably got more error messages about this problem) it is impossible to write
the folder, although you should because there were changes made.
SEE ALSO
This module is part of Mail-Box distribution version 3.010, built on July 18, 2023. Website:
http://perl.overmeer.net/CPAN/
LICENSE
Copyrights 2001-2023 by [Mark Overmeer]. For other contributors see ChangeLog.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl
itself. See http://dev.perl.org/licenses/